1. Field of Invention
The present invention relates to a valve indicator and more particularly to an indicator of the type which indicates the open and closed positions of a valve located below ground level.
2. Prior Art
The typical valve with which the indicator of the present invention is used, is a butterfly valve buried underground in a water line system. Such butterfly valve is movable through 90.degree. between an open and closed position. To indicate the open and closed positions, an indicator is attached to the valve operator. The indicator moves relative to a stationary mounted element or reference point to provide a visual indication of the valve position.
In one such arrangement, the stationary reference point is in the form of a hollow cylindrical housing having diametrically located sighting openings formed therein. The indicator movable with the valve is in the form of a post disposed within the housing and having diametrically extending opening alignable with the cylindrical wall openings. In the open position of the valves, the indicator post opening is aligned with the reference housing openings. In this manner, the visual inspection is easily made from a distance because the inspector may sight through the aligned openings. In the closed or partially closed position of the valve, a portion or all of the indicating post blocks the visibility through the reference openings.
These indicators may be located above ground in areas subject to either vehicle traffic such as tractors, trucks or the like. As a result, the indicators extending above the ground level may be broken off or damaged resulting in the improper or no indication of the valve position.
Heretofore it has been the common practice to permanently attach the indicator post as an extension of the valve operating shaft. In such an arrangement, the extension is sealed from the valve operating shaft to prevent leakage. The sealing has been accomplished by a resilient seal which is compressed by the indicating post which is pinned or otherwise permanently fastened to the extentions. While this arrangement is generally satisfactory in a few instances, as a result of vandalism or a vehicle striking the housing with the reference openings so as to break it off, the post remained erect on the control shaft of the valve. Under these conditions, a sighting is made through the indicator opening without the knowledge that the reference housing is removed and thereby resulting in a false indication.